Ingrain dyeing of synthetic fibers with a furfural solution of ingrain dyes



United States Patent 3,419,340 INGRAIN DYEING 0F SYNTHETIC FIBERS WITH A FURFURAL SOLUTION OF INGRAIN DYES Julian J. Hirshfeld and Byron A. Sample, Jr., Decatur, Ala., assignors to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed July 19, 1965, Ser. No. 473,183 14 Claims. (Cl. 8-32) This invention relates to a novel method of ingrain dyeing synthetic fibers. More particularly, this invention relates to a novel method of producing a color on a synthetic fiber by successively treating the synthetic fibers with furfural and a chemical component selected from the class consisting of aromatic amines, phloroglucinol, and resorcinol.

The term ingrain dyeing defines a process for developing a color directly on a fiber by some type of chemical action between two or more chemicals. More specifically the term defines a process of dyeing a fiber which comprises reacting a first component in situ on the fiber with a necessary second component to form a dye or color onto the fiber. Such a process is usually effected by impregnating the fiber with the first component and then treating the impregnated material with a solution containing the second component, the latter reacting with the first component to form a color on the fiber. This process is characteristic of azoic dyeing.

It is an object of this invention to provide a process of ingrain dyeing synthetic fibers.

Another object of this invention is to provide synthetic fibers dyed ingrain.

It is an object of this invention to provide a process of ingrain dyeing polyester fibers and acrylic fibers.

Still further, it is an object of this invention to provide acrylic fibers and polyester fibers dyed ingrain.

These and other objects of this invention are accomplished by providing a process of ingrain dyeing synthetic fibers selected from the class consisting of acrylic and polyester comprising reacting in situ furfural with a chemical selected from the class consisting of aromatic amines, resorcinol, and phloroglucinol.

The synthetic fibers useful within this invention include polyester fibers and acrylic fibers. Polyester fiber can be defined as a fiber in which the fiber-forming substance is any long-chain synthetic polymer composed of at least 85% by weight of an ester of a dihydric alcohol and terephthalic acid. The acrylic fibers are fibers in which the fiber-forming substance is any long-chain synthetic polymer composed of at least about 80% by weight of acrylonitrile units, i.e.

The acrylic fibers useful with this invention include those obtained from polyacrylonitrile, copolymers including binary and ternary polymers containing at least 80 percent by weight of acrylonitrile in the polymer molecule, and blends comprising acrylonitrile with from about 2 to about 50 percent of another polymeric material the blend having an overall polymerized acrylonitrile content of at least 80 percent by weight. While the preferred polymers useful in the instant invention are those containing at least 80 percent of acrylonitrile, generall recognized as the fiber-forming acrylonitrile polymers, it is understood that the invention is likewise applicable to polymers containing less than 80 percent acrylonitrile. The acrylonitrile polymers containing less than 80 percent acrylonitrile are useful in forming films, coating compositions, molding operations, lacquers, etc.

For example, the acrylic polymer may be a copolymer 3,419,340 Patented Dec. 31, 1968 ICC of from about 80 to about 98 percent acrylonitrile and from about 2 to about 20 percent of another monomer containing the C=C linkage and copolymerizable with acrylonitrile. Suitable mono-olefinic monomers include acrylic, alpha-chloroacrylic and methacrylic acids; the acrylates, such as methylmethacrylate, ethylmethacrylate, butylmethacrylate, methoxymethyl methacrylate, beta-chlorethyl methacrylate and the corresponding esters of acrylic and alpha-chloro-acrylic acids; vinyl chloride, vinyl fluoride, vinyl bromide, vinylidene chloride, l-chloro-l-bromo-ethylene; methacrylonitrile; acrylamide and methacrylamide; alpha-chloroacrylamide; or monoalkyl substitution products thereof; methylvinyl ketone; vinyl carboxylates, such as vinyl acetate, vinyl chloroacetate, vinyl propionate, and vinyl stearate; N-vinylimides, such as N-vinylphthalimide and N-vinyl-succinimide; methylene malonic esters; itaconic acid and itaconic ester; N- vinylcarbazole; vinyl furane; alkylvinyl esters; vinyl sulfonic acid; ethylene alpha, beta-dicarboxylic acids or their anhydrides or derivatives, such as diethylcitraconate, diethylmesaconate, styrene, vinyl naphthalene; vinyl-substituted tertiary heterocyclic amines, such as the vinylpyridines and alkyl-substituted vinylpyridines, for example, 2- vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, etc.; l-vinylimidazole and alkyl-substituted l-vinylimidazoles, such as 2-, 4-, or S-methyl-l-vinylimidazole, and other C=C containing polymerizable materials.

The acrylic polymer may be a ternary or higher interpolymer, for example, products obtained from the interpolymerization of acrylonitrile with two of any of the monomers, other than acrylonitrile, enumerated above. More specifically the ternary polymer may be comprised of acrylonitrile, methacrylonitrile, and 2-vinylpyridine. The ternary polymers may contain preferably from about 80 to about 98 percent of acrylonitrile, from about 1 to about 10 percent of a vinyl-pyridine or a l-vinylimidazole, and from about 1 to about 18 percent of another substance such as methacrylonitrile or vinyl chloride.

The acrylic polymer may also be a blend of a polyacrylonitrile or of a binary interpolymer of from about 80 to about 99 percent acrylonitrile and from about 1 to about 20 percent of at least one other C=C containing substance with from about 2 to about 50 percent of the weight of the blend of a copolymer of from about 10 to about 70 percent of acrylonitrile and from about 20 to about 90 percent of at least one other C=C containing polymerizable monomer. Preferably, when the polymeric material comprises a blend, it will be a blend of a copolymer of from about 90 to about 98 percent acrylonitrile and from about 2 to about 10 percent of another mono-olefinic monomer such as vinyl acetate, with a copolymer of from about 10 to about 70 percent of acrylonitrile and from about 30 to about 90 percent of a vinyl-substituted tertiary heterocyclic amine, such as vinylpyridine or l-vinylimidazole, to give an overall vinylsubstituted tertiary heterocyclic amine content of from 12;?0132 2 to about 10 percent based on the weight of the The polyester fibers useful in this invention are those obtained from the polymerization of aliphatic or aromatic dibasic acids with aliphatic on aromatic diols (glycols) and capable of being drawn into pliable, strong fibers. More specifically and preferably these fibers can be defined as those obtained from any long-chain synthetic polymer composed of at least by weight of an ester of an aliphatic diol and terephthalic acid. Examples of useful polyesters can be found in US. 2,456,319 and US. 3,063,956.

Examples of useful dibasic acids include terephthalic acid, isophthalic acid, dimethyl terephthalate, and pphenylenediacetic acid. Diols or glycols useful within this invention include those of the series HO(CH OH wherein n is an integer within the range of 2 to about 10, e.g., ethylene glycol, tetramethylene glycol, heptamethylene glycol and combinations of glycols within the above formula.

The preferred polyesters of this invention are those obtained from the polymerization of ethylene glycol with either terephthalic acid or dimethyl terephthalate and cpolyesters or modifications of these polyesters. Specific examples of other fiber-forming polymers include pphenylenediacetic acid with ethylene glycol and tetramethylene glycol is isophthalic acid.

The color producing chemicals useful in this invention include the combination of fur-fural, Z-furaldehyde, with a chemical selected from the class consisting of a aromatic amines, resorcinol, and phloroglucinol. Examples of colors produced by the reaction of these two chemicals on the synthetic fiber include a bright scarlet color produced by the reaction of furfural and aniline on an acrylic fiber in an acid medium, an orange color produced by the reaction of furfural and aniline on acrylic fiber in a neutral medium, and a greenish-brown color produced by the reaction of furfural and phloroglucinol on acrylic fiber in an acidic medium.

The color produced on the synthetic fibers depends upon the reaction of the furfural with a strongly activated aro- 'matic nucleus, i.e., activated by an amine group as in analine, or by plural phenolic hydroxyl groups as in phloroglucinol. Useful, strongly activated aromatic nucleus compounds include aromatic amines, resorcinol, and phloroglucinol. Examples of aromatic amines include aniline, phenylene diamine, p-toluidine, alpha-naphthylamine, and any other primary or secondary aromatic amines in which the nitrogen atom is attached to a carbon atom within the aromatic nucleus. Of the aromatic amines, aniline is preferred.

The quantity of furfural and the chemical selected from the class consisting of aromatic amines, resorcinol, and phloroglucinol useful within this invention depends upon the shade of color desired on the fiber and upon the amount of the above chemicals that the fiber will absorb, e.g., acrylic fibers will normally absorb up to about 15% of the chemicals. The molar ratio of furfural to the chemical selected from the Class consisting of aromatic amines, resorcinol, and phloroglucinol varies from about 2:0.5 to about 1:1, respectively. The preferred molar ratio is about 2 moles of furfural per mole of chemical within the specified class. The preferred amount of furfural to be contacted with the synthetic fiber is from about 3% to about 8%, based on the weight of fiber, and this in turn reacted with one of the chemicals within the above class within the molar ratios.

The color produced on the synthetic fiber begins to develop at temperatures above about 140 F. with maximum color being developed at about 180 F. The preferred temperature range for developing the color is from about 170 F. to about 212 F. At higher temperatures, that is in excess of about 220 B, there is a possibility that some detrimental effect Will be caused by the synthetic fiber.

The reaction of the furfural with the above class of chemicals can be carried out under acidic conditions, neutral conditions, and basic conditions. The desired pH range varies from about 4.5 to about 8.0. The color produced on the synethic fiber will depend upon the pH condition at which the reaction takes place and upon the chemical reactant used with furfural. Examples of these variables have been enumerated above.

After the color has been developed on the synthetic fiber, the fiber can be scoured with conventional scouring agents to remove excess reagents, etc. Scouring can be done at temperatures below about 170 F., the preferred temperature range being from about 140 F. to about 160 F. Thereafter the fiber is usually rinsed and dried. The resulting products are wet fast and have a good shade of color developed on the fiber.

The following examples are presented to illustrate various aspects of the invention and are not deemed as limitations. Unless stated otherwise, the parts and percentages throughout the specifications are on a weight basis.

EXAMPLE I A 20 grams fiber sample composed of 93% of acrylonitrile and 7% vinyl acetate is immersed for 20 minutes in a boiling aqueous solution containing 5% by volume of furfural. The sample is removed and spin dried. Thereafter 5 grams of the furfural treated sample is immersed for 15 minutes in cc. of an aqueous solution at 180 F. containing 5% acetic acid and 5 grams of aniline. A bright scarlet shade is developed on the sample. The sample is removed and scoured for 20 minutes at 160 F. in an aqueous solution containing 1% of a nonionic detergent and 0.5% of trisodium phosphate, the percents based on weight of fiber. Examintion of the sample showed excellent wet fastness and a cross-section analysis of the dyed fiber sample showed full penetration.

EXAMPLE II A fiber sample described in Example I is treated as in Example I except there is no acetic acid present. An orange shade is developed on the sample. Examination of the sample showed excellent wet fastness and a crosssection of the dyed fiber sample showed full penetration.

EXAMPLE III A fiber sample described in Example I is treated as in Example I except that phloroglucinol is substtiuted for the aniline. A greenish-brown shade is developed on the sample. Examination of the sample showed excellent wet fastness and a cross-section of the dyed fiber sample showed full penetration.

EXAMPLE IV A 20 gram fiber sample composed of 76.5% of a copolymer being 93% acrylonitrile and 7% vinyl acetate, 10.5% of a copolymer being 50% acrylonitrile and 50% methylvinyl pyridine and 13% polyvinyl chloride is immersed for 20 minutes in a boiling aqueous solution containing 5% by volume of furfural. The sample is removed and spin dried. Thereafter 5 grams of the furfural treated sample is immersed for 15 minutes in 100 cc. of an aqueous solution containing 5% acetic acid and 5 grams of aniline. The aqueous solution is heated to and maintained at 180 F. for 15 minutes. A bright scarlet shade started to develop on the fiber at about F. and increased in depth to 180 F. The sample is removed and then scoured for 20 minutes at F. in an aqueous solution containing 1% of an non-ionic detergent and 0.5% of trisodium phosphate, the percents based on weight of fiber. Examination of the sample showed excellent wet fastness and a fiber cross-section of the sample showed full penetration.

EXAMPLE V A fiber sample described in Example IV is treated as in Example 1V except that phloroglucinol is used instead of analine. A greenish-brown shade is developed on the fiber sample. Examination of the sample showed excellent wet fastness and a cross-section of the dyed fiber sample showed full penetration.

EXAMPLE VI A fiber sample described in Example IV is treated as in Example IV except there is no acetic acid present, An orange shade is developed on the sample. Examination of the fiber sample showed excellent wet fastness and a crosssection of the dyed material showed full penetration.

EXAMPLE "II The procedure of Example I is used to produce a bright scarlet shade on a fiber obtained from the polymerization of ethylene glycol and dimethyl terephthalate.

5 EXAMPLE VIII A rusty brown shade is produced on a fiber sample described in Example I by the procedure of Example I except resorcinol is substituted for the aniline.

EXAMPLE IX The procedure of Example IV is used except there is no acetic acid present and phloroglucinol is substituted for aniline to produce a greenish-brown shade on a fiber obtained from the polymerization of ethylene glycol and terephthalic acid.

EXAMPLE X The procedure of Example IV is used except resorcinol is substituted for aniline to produce a rusty brown shade on a fiber obtained from the polymerization of ethylene glycol and terephthalic acid.

What is claimed is:

1. A process of ingrain dyeing synthetic fibers selected from the class consisting of acrylic and polyester comprising reacting in situ f-urfural with a chemical selected from the class consisting of aromatic amines, resorcinol and phloroglucinol.

2. The process of claim 1 wherein the synthetic fiber is acrylic.

3. The process of claim 1 wherein the synthetic fiber is polyester.

4. The process of claim 1 wherein furfural is reacted with an aromatic amine.

5. The process of claim 1 wherein furfural is reacted with phloroglucinol.

6. A process of ingrain dyeing acrylic fibers compris ing reacting in situ furfural with a chemical selected from the class consisting of aromatic amines, resorcinol and phloroglucinol.

7. The process of claim 6 wherein furfural is reacted with aniline.

8. The process of claim 6 wherein furfural is reacted with phloroglucinol.

9. A process of ingrain dyeing polyester fibers comprising reacting in situ furfural with a chemical selected from the class consisting of aromatic amines, resorcinol and phloroglucinol.

10. A synthetic fiber selected from the class consisting of acrylic and polyester dyed ingrain with the reaction product of furfural with a chemical selected from the class consisting or aromatic amines, resorcinol, and phloroglucinol.

11. The synthetic fiber of claim 10 wherein the synthetic fiber is acrylic.

12. The synthetic fiber of claim 10 wherein the furfural is reacted with an aromatic amine.

13. An acrylic fiber dyed ingrain with the reaction product of furfural and aniline.

14. An acrylic fiber dyed ingrain with the reaction product of furfural and phloroglucinol.

References Cited UNITED STATES PATENTS 1,760,076 5/1930 s Miner 8-l2 2,174,005 9/1939 Miller 893 XR 2,926,060 2/1960 Lehmann 8-31 3,353,900 11/1967 Hirshfeld et al. 8-93 XR FOREIGN PATENTS 852,984 10/ 1952 Germany.

NORMAN G. TORCHIN, Primary Examiner.

a D. LEVY, Assistant Examiner.

U.S. Cl. X.R. 855 

1. A PROCESS OF INGRAIN DYEING SYNTHETIC FIBERS SELECTED FROM THE CLASS CONSISTING OF ACRYLIC AND POLYESTER COMPRISING REACTING IN SITU FURFURAL WITH A CHEMICAL SELECTED FROM THE CLASS CONSISTING OF AROMATIC AMINES, RESORCINOL AND PHLOROGLUCINOL. 